Uniformly Controlled Treble Boundary Using Enriched Adsorption Sites and Accelerated Catalyst Cathode for Robust Lithium-Sulfur Batteries

Rechargeable lithium-sulfur batteries (LSBs) are recognized as a promising candidate for next-generation energy storage devices because of their high theoretical specific capacity and energy density. However, the insulating of sulfur, Li2S2/Li2S, and the shuttling effect of high order lithium polysulfides (LiPSs) hinder its practical applications. Herein, a heterostructure is explored to enhance the conversion reaction kinetics and adsorption ability of LiPSs. By rationally designing a conductive carbon framework and polar metal sites, both experimental and theoretical results show strong adsorption abilities for dissolved LiPSs and promote the conversion reaction rate. A CoSe2/Co3O4@NC-CNT/S cathode shows an excellent rate performance (approximate to 1457 mAh g(-1) at 0.1 C and still retains approximate to 688 mAh g(-1) at a high rate of 5 C). When performing charge-discharge in long-term stability at 2 C, the CoSe2/Co3O4@NC-CNT/S cathode delivers a high initial specific capacity of approximate to 780 mAh g(-1) and retains approximate to 602 mAh g(-1) after 500 cycles with an excellent Coulombic efficiency of approximate to 95.4%. Remarkably, the battery can entirely operate even at a very high sulfur loading of approximate to 10.1 mg cm(-2) and lean electrolyte condition. This work emphasizes a new strategy to rationally design heterostructures that can encourage the industrial application of LSBs.